Last but one TMA. Not one I'm looking forward too as much. Its got essay like things in, and its so easy to lose marks in these. Oh well, after all the biology essays I've done, and skating quickly over the archaeology ones, I ought to be used to this sort of thing, so hey ho.
Question 1
In this one, you have to prepare an overhead transparency for a 1 minute talk. Of course almost no one uses overheads these days, they use powerpoint or similar. Gone are the days (hopefully) of getting acetates shrink wrapped around the photocopier drums. You have to prepare the overhead, on the subject of "The use of VSEPR to predict the structure of tellurium tetrachloride". You then have to write a script that when read aloud will take 1 minute to read in a normal voice and taking breaths etc. Apparently in some previous versions of the course, you actually had to record the talk and post a tape with it on, but thankfully that isn't required now. Your tutor has to read it and decide if you are within the time limits. You can annotate the script a little with markers to show where you are pointing to on the slide.
Anyway, not too bad a question - the topic is fairly striaghtforward, and a few graphics help spice up the slide.
Question 2
This is about book 9 - p-block materials. You have to identify an element given a few facts about its appearance and its reactions with flourine. Then a bit about its oxidation states, and then its reactions with acid and alkalis.
Question 3
Some entropy sneaks back in, as you have to compose a formation reaction for BCL3. Then draw a lewis structure for it.
Thats followed up by a full blown thermodynamic cycle for the construction of it so you can work out the molar enthalpy. Finally an equation for the formation of BCL3 from boric oxide and phosphorous pentachloride.
Question 4
More identification of solids and solutions based on some reactions. Some reactions are described and you have to predict what will be formed, then these in turn react and so on. Of course if you get step 1 wrong, your a bit lost for the rest of the question.
Question 5
Its essay time. "The chemistry of bromine can be predicted from its position in the Periodic Table". A report of 600 words explaining this. You can include graphs, diagrams, pictures, tables etc, and I throw in quite a few of these as it helps give me something to do rather than just writing words, and it also breaks up the structure a bit. Even a picture of dear old Dmitri Mendeleev helps give it a bit of colour.
You have to do all the usual stuff, introduction, conclusion, references etc. Anyway, after a lot of tinkering with it, I get something I'm not altogether happy with, but can't see how to improve it in the time and space available.
So - just one more to go, then the exam looms on the horizon.
Thursday, 28 May 2009
Tuesday, 19 May 2009
S205: Book 10 - Mechanism and Synthesis
Book 10 - the last real book. There is a Book 11, but its more of a pamphlet and discusses how to write essays and make presentations and stuff like that.
Anyway, Book 10 is all back to organics and synthesis.
First there is a whole section on carbonyl compounds and reactions - those things with a C=O in them somewhere. I guess you either like this sort of stuff, or not. I'm rather less than impressed with it all, although the rules seems straight forward there seem to be a lot of them.
Then the next section is all about organometallic reactions. Grignard reagents. Despite not really knowing how these are made, they seem awfully useful for glueing bits of molecules together.
It starts with magnesium compounds, then we move through into sodium, lithium and copper compounds. Then it finishes up with organoboron.
Section 3 looks at radical reactions - where you get compounds with single electrons lieing around. These use to be so rapid and violent to be unusable, but recent times they have found ways of taming them to make a useful way of doing things.
Section 4 is about retrosynthesis mostly. So knowing what you want to make, how can you work backwards to find a way to make it from everyday molecules. Basically there is no right way or wrong way, but some rules help you to break up compounds to make it easier. It seems a combination of science, experience and a touch of art.
The last section looks at biosynthesis, which rather puts chemist in the shade. Making complex molecules at room temperature and pressure without breaking a sweat.
Finally, there is a case study on polymers.
Phew - all done - finally got to the end of what has been a long course squeezed into what seems too short a time!
Anyway, Book 10 is all back to organics and synthesis.
First there is a whole section on carbonyl compounds and reactions - those things with a C=O in them somewhere. I guess you either like this sort of stuff, or not. I'm rather less than impressed with it all, although the rules seems straight forward there seem to be a lot of them.
Then the next section is all about organometallic reactions. Grignard reagents. Despite not really knowing how these are made, they seem awfully useful for glueing bits of molecules together.
It starts with magnesium compounds, then we move through into sodium, lithium and copper compounds. Then it finishes up with organoboron.
Section 3 looks at radical reactions - where you get compounds with single electrons lieing around. These use to be so rapid and violent to be unusable, but recent times they have found ways of taming them to make a useful way of doing things.
Section 4 is about retrosynthesis mostly. So knowing what you want to make, how can you work backwards to find a way to make it from everyday molecules. Basically there is no right way or wrong way, but some rules help you to break up compounds to make it easier. It seems a combination of science, experience and a touch of art.
The last section looks at biosynthesis, which rather puts chemist in the shade. Making complex molecules at room temperature and pressure without breaking a sweat.
Finally, there is a case study on polymers.
Phew - all done - finally got to the end of what has been a long course squeezed into what seems too short a time!
Tuesday, 12 May 2009
S283: TMA-1
Well compared to the chemistry I'm doing alongside this, I find this TMA reasonably easy. Possibly too easy as I get a less than expected mark for it. That will teach me!
Lets see - what does it have in store?
Question 1 is about the formation of the solar system. When it formed, why rocky planets are in the inner and gas giants in the outer. Stuff about ring systems and density, and the asteroid belt. Not too bad for a start.
Question 2 is geology. What the structure of the earth is, what the layers are, how they are defined and stuff like that. Some bits on mineralogy and seismic data, and rounded off with xenoliths and what they can tell us about the structure.
Question 3 looks at various moons, and gets you to fill in a table. How old is the surface of each, what if any caused the resurfacing, and what was it made up of. Then you are given data about two imaginary satellites, and asked to work out from density and other information what sort of body they are likely to be.
Question 4 is about volcanism and cryovolcanism. What basalt is so common, what makes it so and so on. More geology...
Question 5 is interesting, as you are given a picture of part of the moon, and have to work out various dimensions of the craters pictured, and then determine if they are simple or complex craters. I found acrobat reader has a great tool for this sort of measuring. Then you have to make various observations and hypotheses about the craters such as age and relative order.
Lets see - what does it have in store?
Question 1 is about the formation of the solar system. When it formed, why rocky planets are in the inner and gas giants in the outer. Stuff about ring systems and density, and the asteroid belt. Not too bad for a start.
Question 2 is geology. What the structure of the earth is, what the layers are, how they are defined and stuff like that. Some bits on mineralogy and seismic data, and rounded off with xenoliths and what they can tell us about the structure.
Question 3 looks at various moons, and gets you to fill in a table. How old is the surface of each, what if any caused the resurfacing, and what was it made up of. Then you are given data about two imaginary satellites, and asked to work out from density and other information what sort of body they are likely to be.
Question 4 is about volcanism and cryovolcanism. What basalt is so common, what makes it so and so on. More geology...
Question 5 is interesting, as you are given a picture of part of the moon, and have to work out various dimensions of the craters pictured, and then determine if they are simple or complex craters. I found acrobat reader has a great tool for this sort of measuring. Then you have to make various observations and hypotheses about the craters such as age and relative order.
Monday, 11 May 2009
S205: TMA-4
Another TMA - and they are coming thick and fast at this point. Two TMA's due in the same month! This TMA is a bit of a monster, but turns out to get my best mark so far, so maybe something is sinking in - although I suspect its just how it goes.
Question 1 is about analysis. You are given some weights of elements found in a compound and asked to work out the empirical formula for it. Its really not too difficult, as its sort of like the S103 stuff, but a bit more complex. A nice surprise after some of the nightmare questions!
Question 2 is all about identifying struture. Youy are given IR and NMR spectroscopy data, and based on this and the molecular formula, you have top work out what the structure is. I find the NMR pretty good to do. The IR is a little vague, but you can answer it pretty much just from the NMR data, and use the IR for confirmation.
Question 3 is NMR from the other direction. Given a particular structure, you need to predict what NMR peaks and troughs it should give you. Its not too bad - once you get the idea of carbon equivalence.
Question 4 is looking at oxoacids, and working out their strengths. Its fairly straightforward if you can relate it to Paulings rules and coefficients.
Question 5 is to write an essay plan for the essay that has to be written for TMA-5. An essay - in chemistry, I never thought I'd see the day! Oh well...
As I said, not a bad TMA - which I think is more down to the absence of complex organic reactions than anything else.
Question 1 is about analysis. You are given some weights of elements found in a compound and asked to work out the empirical formula for it. Its really not too difficult, as its sort of like the S103 stuff, but a bit more complex. A nice surprise after some of the nightmare questions!
Question 2 is all about identifying struture. Youy are given IR and NMR spectroscopy data, and based on this and the molecular formula, you have top work out what the structure is. I find the NMR pretty good to do. The IR is a little vague, but you can answer it pretty much just from the NMR data, and use the IR for confirmation.
Question 3 is NMR from the other direction. Given a particular structure, you need to predict what NMR peaks and troughs it should give you. Its not too bad - once you get the idea of carbon equivalence.
Question 4 is looking at oxoacids, and working out their strengths. Its fairly straightforward if you can relate it to Paulings rules and coefficients.
Question 5 is to write an essay plan for the essay that has to be written for TMA-5. An essay - in chemistry, I never thought I'd see the day! Oh well...
As I said, not a bad TMA - which I think is more down to the absence of complex organic reactions than anything else.
Wednesday, 25 March 2009
S205: CMA-2
So - there is another computer marked assignment to do. There are 35 question to be done, and they vary a lot in format. Some you have to work out a number and type it in. Others require ticking boxes, and so on. These have their strengths and weaknesses. Firstly its a computer marking your efforts, although the questions are reviewed by the course team. This does mean you can sometimes get what you think is the right answer only to be caught out on a technicality, like typing 2.0 when it is expecting 2. Mostly though its pretty good at taking reasonable answers - but of course can't apply the same common sense a human can.
You generally get 3 attempts at an answer, unless its a true/false type one. A couple of them I got completely wrong. One was on the symmetry of SeOCl4 using VSEPR - which even after 3 attempts I still got wrong, and couldn't work out why. My tutor suggested some possibilities given I knew the answer (it tells you once you get it wrong). I also checked it out with a chemistry lecturer friend and she came to the same conclusion as I had. After taking it up with the course team they explained (after the deadline) why their answer was right, but eventually they zero'd out the question as it was rather ambiguous. Even given the answer I couldn't see how you could come up with a definitive structure based on just the course notes - there simply wasn't enough data to cover these weird edge cases. The trouble with issues like this is that I find it suddenly undermines my confidence. Its not a silly mistake, its something I've thought about and still got wrong. I suppose whatever doesn't fail makes me stronger, but in reality it tends to lead to a certain fear of similar questions.
The other question I got wrong I could eventually see I'd just made a silly mistake. Its a bit weird doing these things, you tend to get CMA blindness. For instance I'd take all the data given, do all the calculations and come up with an answer - I'd probably check it too - and then look at the screen and see if my answer was there. If it was, I'd tick it, if not then I clearly need to try again. However often you get one of these calculations where you end up doing a load of steps and then the final one is to multiply by 2 -- or is that divide by 2... after due consideration you decide its multiply by 2, see the answer is there, tick and go. Wrong answer. My immediate reaction is not to do any more work (because I'm lazy by nature) but to assume it was divide by 2, and the answer is there to, so tick that and resubmit immediately without rechecking things. Wrong again! This is where you're 3rd chance comes in, and where you should sit down and rework the problem again - rather than phoning a friend or asking the audience.
Anyway - that was the last of the two CMAs in this course.
You generally get 3 attempts at an answer, unless its a true/false type one. A couple of them I got completely wrong. One was on the symmetry of SeOCl4 using VSEPR - which even after 3 attempts I still got wrong, and couldn't work out why. My tutor suggested some possibilities given I knew the answer (it tells you once you get it wrong). I also checked it out with a chemistry lecturer friend and she came to the same conclusion as I had. After taking it up with the course team they explained (after the deadline) why their answer was right, but eventually they zero'd out the question as it was rather ambiguous. Even given the answer I couldn't see how you could come up with a definitive structure based on just the course notes - there simply wasn't enough data to cover these weird edge cases. The trouble with issues like this is that I find it suddenly undermines my confidence. Its not a silly mistake, its something I've thought about and still got wrong. I suppose whatever doesn't fail makes me stronger, but in reality it tends to lead to a certain fear of similar questions.
The other question I got wrong I could eventually see I'd just made a silly mistake. Its a bit weird doing these things, you tend to get CMA blindness. For instance I'd take all the data given, do all the calculations and come up with an answer - I'd probably check it too - and then look at the screen and see if my answer was there. If it was, I'd tick it, if not then I clearly need to try again. However often you get one of these calculations where you end up doing a load of steps and then the final one is to multiply by 2 -- or is that divide by 2... after due consideration you decide its multiply by 2, see the answer is there, tick and go. Wrong answer. My immediate reaction is not to do any more work (because I'm lazy by nature) but to assume it was divide by 2, and the answer is there to, so tick that and resubmit immediately without rechecking things. Wrong again! This is where you're 3rd chance comes in, and where you should sit down and rework the problem again - rather than phoning a friend or asking the audience.
Anyway - that was the last of the two CMAs in this course.
Tuesday, 10 March 2009
S205: Book 9 - Elements of the p-block
Oh no -its another vast book - 242 pages about lots of stuff - its information overload, and I'm not really sure what you are suppose to take away from this book. There seems far too much to learn, so in the end I just end up reading the book and hoping some of the concepts sink in ... hummm.
It starts off of, by looking at oxidation states and how you can work them out from various rules. That's not too bad.
The next chapter starts to look at acids and bases, and in particular extends the definition to Brønsted acids - which are compounds that can donate a proton or hydrogen ion.
So having just got the idea of a new type of acid, we have another new type in the next chapter - the Lewis acid. This is a substance that can donate a pair of electrons. Okkkayyy - just about getting that.
Next chapter is all about the chemistry of hydrogen - what it can do and how it can form hydrides and things like that. I'm sure there is some general message here but it seems like just a large number of different reactions.
Next we look at halides, and all manner of ways that the halogens can form compounds. Again a confusing number of different reactions.
After that - a real walk on the wild side as we look at those most unreactive of elements, the noble gases and the various compounds they can form. Its a bit like being told there is no Santa Claus that compounds of the noble gases can form compounds. I mean - the one thing you generally learn in chemistry is that compounds struggle to form bonds to make noble gas like electron shells. Then along comes xenon, and starts disrupting these well rehearsed truths.
After a brief foray into some trends in second and third row elements (which is also covered - better for me - in a dvd accompanying the book), we launch into group 3. Boron, aluminium and so on. Boron is plain weird, it eschews the eightfold way and is happy to make compounds with only a shell of 6 electrons. Its all rather disconcerting.
Then its time to look at group 4. Carbon, silicon and their ilk. It seems we've been doing precious little other than looking at carbon for most of this course, but here it is again.
Follow this up with a look at group 5 nitrogen, and phosphorous, and all they can do. Then its on to oxgen, sulphur and its pals.
Finally another look at trends and the book is done, except for a case study look at acid rain.
So much information, so many reactions - my head is spinning. How can anyone possibly remember a 10th of this stuff.
It starts off of, by looking at oxidation states and how you can work them out from various rules. That's not too bad.
The next chapter starts to look at acids and bases, and in particular extends the definition to Brønsted acids - which are compounds that can donate a proton or hydrogen ion.
So having just got the idea of a new type of acid, we have another new type in the next chapter - the Lewis acid. This is a substance that can donate a pair of electrons. Okkkayyy - just about getting that.
Next chapter is all about the chemistry of hydrogen - what it can do and how it can form hydrides and things like that. I'm sure there is some general message here but it seems like just a large number of different reactions.
Next we look at halides, and all manner of ways that the halogens can form compounds. Again a confusing number of different reactions.
After that - a real walk on the wild side as we look at those most unreactive of elements, the noble gases and the various compounds they can form. Its a bit like being told there is no Santa Claus that compounds of the noble gases can form compounds. I mean - the one thing you generally learn in chemistry is that compounds struggle to form bonds to make noble gas like electron shells. Then along comes xenon, and starts disrupting these well rehearsed truths.
After a brief foray into some trends in second and third row elements (which is also covered - better for me - in a dvd accompanying the book), we launch into group 3. Boron, aluminium and so on. Boron is plain weird, it eschews the eightfold way and is happy to make compounds with only a shell of 6 electrons. Its all rather disconcerting.
Then its time to look at group 4. Carbon, silicon and their ilk. It seems we've been doing precious little other than looking at carbon for most of this course, but here it is again.
Follow this up with a look at group 5 nitrogen, and phosphorous, and all they can do. Then its on to oxgen, sulphur and its pals.
Finally another look at trends and the book is done, except for a case study look at acid rain.
So much information, so many reactions - my head is spinning. How can anyone possibly remember a 10th of this stuff.
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